1. Field of the Invention
The present invention relates to a slider, a head assembly and a disc apparatus, and more particularly to a slider suitable for improvement of floating stability, a head assembly having the slider and a disc apparatus having the head assembly.
2. Description of the Related Art
The slider is a member for stably floating a head element above a medium such as a rotating magnetic disc by means of air lubrication. The general structure of the slider is disclosed in, for example, the following patent document 1 and patent document 2. The disc facing surface of the slider has a protruded positive pressure-generating section on four portions, namely the side of an air inflow end, the side of an air outflow end and one pair of portions separated from each other in the breadth direction. In addition, a recessed negative pressure-generating section is formed in substantially the center of the disc facing surface. Besides, a curved portion called as a crown is formed on the disc facing surface of the slider in its longitudinal direction, and a curved portion called as a camber is also formed in a direction perpendicular to the longitudinal direction.
[Patent Document 1] Japanese Patent Laid-Open Application No. 2003-308671
[Patent Document 2] PCT International Publication No. WO-A1 99/48098
In recent years, with miniaturization of the disc apparatus, the slider has also become small. The size of the slider is standardized by IDEMA (International Disc Drive Equipment and Materials Association) and the slider is named as a mini-slider, a micro-slider, a nano-slider, a pico-slider and a femto-slider in decreasing order of size. Among them, the femto-slider having a disc facing surface of about 850 μm×700 μm is particularly hard to improve an air film rigidity in a roll direction. Thus, a change in floating amount involved in variations in steady attitude in the roll direction (roll static attitude: RSA) and a deviation of a load point in the roll direction by suspension might become problems.